Telephone-key.



W. KAISLING.

TELEPHONE KEY.

APPLICATION men MAR. 7. 1901. RENEWED OCT. 2. 1911.

1,176,759. Patented Mar. 28,1916.

2 SHEETS-SHEET 1.

M IL LIAM fiA/SL/NG WW m THE COLUMBIA PLANOGRAPH $0.. WASHINGTON. B. C.

W. KAISLING.

TELEPHONE KEY.

APPLICATION FILED MAR-7.1907. RENEWED OCT. 2. 1911.

1,176,759. Patented Mar. 28, 1916.

2 SHEETSSHEET Z.

THE COLUMBIA PLANnuRAPH cm, WASHINGTON, D. C.

WILLIAM KAISLING, F CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO KELLOGG SWITGHBOARD & SUPPLY COMPANY, A CORPORATIQN .OF ILLINOIS.

TELEPHONE-KEY.

Specificationof Letters Patent.

Patented Mar. 28, 1916.

- Application filed March 7, 1907, Serial No. 361,130. Renewed October 2, 1911. Serial No. 652,412.

T 0 all whom it may concern:

Be it known that 1, WILLIAM KAIsLING, a citizen of the United States, and resident of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Telephone-Keys, of which the following is aspecification.

The present invention relates to telephone keys such as are employed in operators linkcircuit connecting apparatus and has to do more particularly with that type known as listening and ringing keys, by the use of which the operator can include her telephone set in circuit and apply ringing current to the line for signaling purposes, and especially for signaling one of a number of subscribers on the line. I

The principal object of the invention s to provide a key of the character indicated, possessing certain novel features of construction together with a novel arrangement of parts which enable the key to be economically manufactured while leaving it compact and simple in construction and efficient in operatlon.

One of the eatures of the invention consists of a novel catch ,mechanlsm for malntaining the different actuatlngmembers of the key in their various operating positions Another feature consists in the employment of novel means for restoring the'listenring key to its normal position upon the operation of any one of the ringing keys.

The invention also includes other features and details which, together with the above, will be more fully understood upon reference to the following detailed description taken in connection with the accompanying drawing, and the scope of the invention will be particularly pointed out in the appended claims.

Referring to the said drawing, Figures 1 to 6 inclusive illustrate a combined ringing and listening key constituting one form of the invention, while Figs. 7 to 1 1 inclusive illustrate a similar key constituting a sec ond form. Fig. l is a side elevation of the key constituting the first form; Fig. 2 is a similar elevation of a portion of the same, illustrating a ringing key in its fully depressed position; Fig. 3 is an end elevatlon of the same, viewed from the right; Fig. l is a fragmentary elevation of the same, viewed from the left; Fig. 5 1s a detalled section taken on a plane indicated by the line 5-5 of Fig. 1; Fig. 6 is a diagram of circuits lllustrating one use of said key; Fig. 7 is a slde elevation of the key constituting the second form of the invention, parts being broken away for clearness; Fig. 8 is a vertical section taken on a plane indicated by the llne 88 of Fig. 7; Fig. 9 is a frag mentary end elevation of the key, viewed from the left; Figs. 10, 11, 12 and 13 are views illustrating different operative positions of the catch-bar and an engaging pin of one of the ringing keys; and Fig. 1 1 is a diagram of circuits illustrating one application of said key.

Throughout these views like characters refer to like parts.

In each form of the invention, the com bined key construction includes a plurality of ringing keys of the plunger type in assoclation with a listening key of the lever type, all mounted compactly upon an elongated frame. In each of these forms, each longitudinally movable key has three operatlng positi0nsa normal, a fully depressed, and an intermediate position, the fully depressed position beingthe ringing position, and the intermediate position an indicating position. In each form, longitudinally movable catch-bars cooperate with the ringing keys in retaining them in their various 0peratlng positions, and with the listening key to cause its restoration upon the operation of any of the ringing keys. In the form of the invention illustrated in Figs. 7 to 14 in elusive, armature mechanism of an electromagnet cooperates with the catch-bars in accordance with prodetermined circuit conditions, occasioned by specific acts performed while establishing a conversational circuit between subscribers.

Referring in detail to the drawing and at first to Figs. 1 to 6 inclusive, the various partsjare mounted on a suitable supporting frame including the vertical members 10 united at their lower ends by plates 11 and at their upper ends by a strip 12 provided with a suitable face-plate 13. The strip 12 and face-plate 13 are provided with suitable openings through which the listening key lever L and each of a plurality of ringing keys KK K 'K extend. The keys K-K 'K K extend downwardly into position to engage the upwardly extending sets of spring contacts SS S S respectively. The springs are secured at their lower ends by a suitable insulating member 1-lpreferably secured between the plates 11 by screws 15 and arranged so as to properly space the springs of each set in the manner illustrated. The insulating member 14. is provided with suitable guiding openings through which the lower ends of the keys KK -KIt:' are adapted to pass. The guiding ends of these keys are reduced in diameter and each is provided with a coiled returning spring 16 lying in close proximity to it and hearing at its opposite ends against the upper face of the insulating member l l and a shoulder on the corresponding key. Each of the keys KK-IC*--K is adapted to occupy three operating positions, referred to as normal, indicating and ringing positions. In the normal position, a shoulder 17 on the shank of each key rests against the under face of the strip 12, and the spring contacts of the particular set. remain out of engagement. As clearly illustrated, each set of contacts S$ S S consists of an actuated contact 18 and a co operating contact 19. Contact 18 is somewhat longer than'contact 19 and its upper end bears against the insulating block 20 carried by the shank of the key. This shank is adapted to cooperate with an inclined portion 21 of the spring 18. The cooperating inclined face is preferably provided by giving the spring contact 18 an angular bend such as clearly shownin Fig. 1. As the key is moved downward, the insulatingblock 20 engages the inclined portion 21 and the contacts 18-19 are moved into engagement, as illustrated in Figa 2. Each keyis provided with a laterally pro ecting pin 22, having a horizontal upper face, adapted to cooperate with catch projections 23 formed in the walls of openingsof a longitudinally movable catch -bar 24:. The outer ends of the pins 22 extend through vertical guiding slots 25, formed in the guiding plate 26 which is fixed in position upon the frame, in the present instance by screws 27 threaded into the vertical frame members 10. In this form of the invention,-

' ably mounted at their lower ends on an insulating block 35 located at one end of the supporting frame in line with the insulating member 1 1 and preferably secured by a screw 36 to the adjacent member 10 of the frame. By reason of the inclination of the cooperating faces. of the spring. contacts 29 30 and the insulating button 28, the bar 24: tends to occupy the position illustrated in Fig. 1,

' the latter springs back intoengaging position and the key will be held thereby from returning to normal. This catch is located,

however, so as to engage the pin 22 when the key is in an intermediate or indicating position. Further downward movement of the key will therefore bring the lower face of the pin 22 into engagement with an inclined face 37 of the bar 24: and thereby forcibly move the same farenough to actuate the spring contacts 29-30. I /Vh'enthe depressed key has reachedthis position,its insulating, block 20 will have engaged the inclined portion 21 of the contact 18, and the latter will have been forced into engagement with its associated spring contact 19. The keywill remain in this fully depressed position only as long as force is applied to it. As soon as such force is removed, the key will tend to return to its normal position under the action of its returning spring 16, and the bar 24 willmove to the right under the action of the springcontacts 29 and 30 upon the insulating button 28. This return movement is also assisted by a leaf-spring 38 which bears at its upper end against the left-hand end of the bar 2dand is firmly secured to the frame member 10 at its lower end. As a result of the removal ofpressure from the depressed key, therefore, it will return until the upper face of the pin 22 engages the lower face of the catch 23. It will. be held in this position until the catch-bar 2 1 is again reciprocated as a result of depressing another ringing key. By providing this indicating position, the operator can readily determine which key was last depressed, in case it is desired to again apply ringing current to the line, as will hereinafter more fully appear.

As previously indicated, the key structure includes the listening key lever L which extends through a suitableopening in the strip 12 and face-plate 13 and is pivoted at the point 39 to said face-plate. The lower circular portion of the lever L is provided with shoulders a041 which are adapted to engage the under side of the strip 12 to limit the movements of the lover. The lower end of the lever is provided with a projection a-ting contacts 4:34: l. The contacts of each 7 pair are normally out of engagement as illustrated 1n F 1g. 1, but are adapted to be pressed into engagement by the movement of the lever L to the dotted line position of said figure. The set of spring contacts S is suitably secured to an insulating block 45 secured to the adjacent frame member 10. The upper end of the contacts 43 are inclined and so positioned thatupon the movement of the lever L to its dotted line position, it will be retained in such position by reason of the relative position of the pivot point 39 and the point at which the force of the springs is applied. By reason of this bias, a slight movement of the lever L from its dotted line position toward its normal position will free it and allow it to return to normal under the action of the springs 48. For the purpose of returning the lever L whenever one' of the ringing keys KK K K* is depressed, the bar 2a is provided with a projection 46 which engages the lower portion of the lever L'whenever said bar is actuated; and as a result, the lever L is moved far enough to allow it to return to normal under its bias.

In the diagram of Fig. 6, I have illustrated a portion of a link'circuit and a telephone line, having a plurality of substations, associated with it, withwhich the combined ringing and listening key, above" described, may be employed. In the system ofthis diagram, selective ringing of the character described in Patent N 0. 779,533, granted J an. 10, 1905, is employed. According to this arrangement, generators GG G G are designed to give current of different frequencies, and the callbells ZJZ) 0 at the substations are designed to respond only to current of the frequencies of the generators. In other words, the application of ringing current from generator G will be instrumentalin actuating one of the call-bells only, as, for example, call-bell 6', current from generator G will actuate thecall-bell b and so on. Assuming that the link-circuit of the diagram is connectedwith a calling line and that the operator has thrown her listening key lever L, so as to close each pair of contacts e3-4 l and thereby. include her telephone set S in circuit, and that itis learned that connection is desired with one of the substations on the line L, say, for example, the substation having call-bell b; then, after testing the line L in the usual manner, the operator will inform the calling party if the line is in use; and if not, she will insert the calling plug P into a jack J of the line L and depress the appropriate ringing key K-K K K Let it be assumed that the proper key to actuate the call-bell b is that designated K.

Upon depressing the key K, the catchin its indicating position will be releasedv and allowed to return to normal. The depression of key K to its ringing position will throw contacts fail-30 to their alternate positions and at the same time close con-- tacts 1819 of the ringing key K. Thereupon current will be supplied from the battery B through the resistance e7, contacts 3d80, plug and jack sleeve contacts, through the winding of cut-off relay d8 to ground, thereby actuating the cut-off relay and maintaining it actuated. At the same time, ringing current will be applied to the tip side of the circuit from the generator G over a path which may be traced from the live pole of the generator, through contacts 18 19 of key K, contacts 3329, plug and jack tip contacts, through the call-bells at the various substations, and back through the winding of the cut-otf relay to ground. By reason of the frequency of the current supply, the call-bell 5 only will be actuated. As previously indicated, ringing current will be applied to the line only when the key K is fully depressed; and as soon as the operator removes her finger from the key, it will return to its intermediate or indicating position and thereafter, if it becomes necessary to again signal the party at the substation previously called, she may readily determine which key should be again depressed. In this instance, the removal of the plug P from its jack J at the end of conversation will not affect the position of the ringing key K, but it will be restored only upon the subsequent depressing of another ringing ke K K or K. In this connection, it should also be noted that upon the first full downward pressure of the ringing key K, the listening key lever L was returned to its normal position.

Referring now to the form of the invention illustrated in Figs. 7 to let inclusive, it will be seen that the key parts are mounted on a. similar rectangular supporting frame comprising vertical members 50 secured at their lower ends by plates 51 and connected at their upper ends to a strip 52 upon which the face-plate 53 is mounted. As before, the face-plate and the supporting strip are provided with suitable openings through which the listening key lever L and the longitudinally movable ringing keys 7c la 7c -k extend. As before, these keys extend downward into positions to engage the upwardly projecting sets of contacts s's s s which are firmly secured and spaced at their lower ends by the insulating member 54: located between the plates 51 and firmly seouredthereto, preferably by screws 55. The insulating member 54 is provided with suitable guiding openings through which the lower ends of the keys 7a-7c 7c 7c are adapted to pass. The guiding ends of these keys, as before, are reduced in diameter and each is provided with a suitable returning spring 56 closely coiled about it and bearing at itsopposite ends against the member 5% and a shoulder of the corresponding key. Each of the keys is adapted to occupy three operating positions-namely, a normal, an intermediate or indicating, and a fully depressed or ringing position. In Fig. 7, keys lclc lc* are shown in their normal positions, while 70 is shown in its fully depressed position. In this figure, the dotted line position of the key 70 shows said key in its intermediate or indicating position. In the normal position, a shoulder 57 on the shank of the key engages the under face of the frame strip 52, and the engaging ends of the contacts 5859 and 60-6l of the particular set of spring contacts s-s s s are held out of engagement. The inner contacts of each of these pairs bear against the opposite sides of an insulating block 62 carried by the key and the contacts are bent at a point just above the upper ends of the contacts 58 and 60 so as to form angular portions 63-64-, against which the block 62 is adapted to press upon the downward movement of the key to close the contacts 58-59 and 60-61. Each of the keys 70'-. c 7c -7c* is also provided with a lateral projecting pin 65 having its upper side and a portion of its lower side flattened so as to present horizontal engaging faces. These pins project through openings in the longitudinally movable catch-bars 6667 and through guiding slots 68 in the fixed plate 69, which is preferably secured to the frame members 50 by the screws 7 0. As clearly shown in Fig. 7, each of the catch-bars 66-67 is provided with an angular catch for cooperation with the associated pin 65. These catches, which are designated, respectively, 71 and 72, are each provided with an upper inclined face and a lower horizontal face. The catches 7172 are in horizontal alinement and so positioned with reference to the pin 65 as to engage the upper face of said pin when the key is in its ringing position. Bar 66 is also provided, on the opposite side of each opening from the catch 71, with a rectangular catch projection 73. The catch-bar 66 is pressed toward the right, as viewed in F ig. 7, by a leaf-spring 74 suitably secured at its lower end to one of the frame members 50 and bearing at its free end against the left-hand end of said bar. On the other hand, the catch-bar 67 is pressed toward the left by a similar leaf-spring 7 5 secured in like manner to the frame member 50 at the opposite end of the frame. As before, the key lever L is pivoted at 76 to the frame strip 52, is limited in its movement by the shoulder stops 7778, and is provided with a projection. having an insulated covering 7 9 which is adapted to engage the upper inclined ends of the spring contacts 80. This set includes two pairs of contacts 80*81;

which are secured and spaced at their lower ends by a suitable insulating block 82, preferably secured by screws 83 to the lower .end of the adjacent frame member 50. fore, the movement of the listening key lever L to the left forces the spring contacts into engagement with their associated contacts 81, and the action of these spring contacts is such as to returnthe lever L to its normal position until it has been moved to the leftbeyond a certain point. Then, as before, it is retained in its actuated position. As before, also, the listening key lever. L is adapted to be moved-from its actuated position, so that it will be free to return under its bias, by a projection 84 on the catch-bar 67. At the opposite end of the key structure, is mounted an electromagnet E whose angular frame 85 has its short side secured to the under-face of the strip 52, and its long side projecting downward parallel to the adjacent frame member 50. The electromagnet controls an armature 86 of the usual angular type, pivotally secured at its angle to the lower end of the frame 85 by a pivotal pin 87, and having its upwardly of spring contacts s, supported and, spaced at their lower ends by an insulating member 89, preferably secured by screws90 to the lower end of the magnetframe 85.. The upper end 88 of the armature 86 also cooperates with a projection 91 extending from the end of the catch plate 66 into close proximity thereto. As the armature is attracted, its upper end 88 engages the projection 91 and forces the catch-bar 66 longitudinally against the pressure of its spring 7d. The set of-contacts 8 includes six 00- operating contacts 92,+93-949596 97, which are designed to vary the electrical circuit connections'in a manner hereinafter more fully described. g

Havingnow. described the structure of the key forming the second embodiment of the invention, its operation will be presented in connection with the diagram of Fig. 14 which illustrates the calling end of an operators link-circuit L in conjunction with a telephone line If extending to a plurality of substations l M -M M*. This line is provided at the central-ofiice with the usual line relay 100, controlling the line signal 101, and the cut-off relay 102 by which the normal line limb connections to ground and battery are replaced by connections with the terminals of the jacks J. Assuming that a calling party has initiated a call and obtained connection with the answering end of the link-circuit P, then the operator will throw over her listening LS V projecting end 88 arranged to operate'av set key lever L to close each pair of listening key contacts 80-81 to include her operators set 8 in circuit with the telephone of the calling party. Having learned that the substation wanted is located on the line L*, the operator will at once insert the calling plug P into the jack J of the line L and depress the appropriate ringing key is, 70 70 or 771*. As in the previous diagram, a harmonic system of selective signaling is employed. Of the contacts 5859 and 6061 of each set of ringing key contacts s s s s*, the contacts 58 are severally connected to ground through the generators g-g -g g*, and the contacts 60 are connected to'ground through the common interrupter 1. Assuming that the called-for party is at substation l and that the callbell b at said substation is attuned to respond to the current from the generator 9, then the operator will depress ringing key 70 as soon as she has inserted the. plug P into the jack. The downward movement of the key 7;" will cause the lower rounded portion of the pin to engage the upperinclined faces of the catches 7172 on the catch-bars 6667 respectively, the catch 72 being also engaged since at this time the bar 67 lies in its engaging position as a result of the previous operation of the listening key lever L The continued downward movement of the key will therefore force the catch-bars 66-67 to the left, as viewed in Fi 7; and by the movement of catchbar 6 move listening key lever L far enough to allow it to return to normal under the bias produced by the spring contacts 80. Then, as soon as the pin 65 has moved far enough to allow the catch 71 to slip over its upper face, the catch-bar 66 will return slightly toward the right to the position illustrated in Fig. 11. This occurs when the key has reached its fully depressed position and the ringing spring contacts 5859and 6061 have been moved into engagement. Now, if it be assumed that the line L is idle at this time, the insertion of the plug P into the jack J will cause a flow of current from the intermediate tap of the battery B (which may, for example, supply current of the pressure of eight volts) through the polarized relay 103, normal contact 104 of sleeve supervisory relay 105, contacts 106-407 of relay 108, plug and jack sleeve contacts, and the winding of cut-oft" relay 102 to ground. The direction of this current flow through the polarized relay 103 is such as to move the armature contact 109 to the left into engagement with contact 110, thereby completing a circuit for the sleeve supervisory relay from the live pole of thebattery B" (which may supply current at a pressure of, say, twenty-four volts) through the winding of relay 105 and contacts 110109 to ground, thus energizing .tacts 61 of the ringing keys.

said relay to move its contact 104: to its alternate position and thereby interrupt the energizing circuit of the polarized relay 103 and complete a new path for current through the winding of supervisory relay 105, which may be traced from the live pole of the battery B, through said winding, alternate contact 104, closed contacts 106107, plugs and jack sleeve contacts and cut-off relay 102 to ground. The energization of relay 105 also closes itscontacts 111-112-113. By the closing of contact 113, a path for current is completed through the supervisory lamp 111, which extends from the live pole of the battery 13, through said lamp, normal contact 115 of the tip supervisory relay 116, and closed contact 113 to ground. The closing of contact 111 completes a path for current from the live pole of the battery, through said closed contact, to and through the winding of the so-called flip-flop relay 117 to the con- The closing of contact 112 likewise completes a path from the contact 118 of the flip-flop relay 117, through closed contact 112, closed contact 119 to the tip contact of the calling plug P The full downward movement of the key k for the purpose of supplying ringing current to actuate the call-bell b at substation M will therefore, when the parts have reached this point in their operation, close the ringing key contacts 58-59 and 60-61 of set 5" and immediately a flow of current will result through the flipflop relay 117; and as the interrupter I rotates, the relay will be successively energized and denergized to move its contact 118. Then this contact is in its alternate position, current will be supplied from the generator G, through the contacts 58-59 of key is, alternate contact 118, closed contact 112, closed contact 119, plug and jack tip contacts, thence tothe tip limb of the line, through the substation, back over the sleeve limb and through the winding of the cut-off relay to ground. By reason of the action of the relay 117, this ringing current is intermitttently applied and this intermittent application is continued until the called-for party responds. As soon as he does this by removing his receiver from its hook, a path for battery current is completed through the sleeve supervisory relay 105 to the winding of the cutoff relay 102 as before, thence by one path through said winding to ground; and by another, over the sleeve limb of the line through the substation, back over the tip limb of the line, through the plug and jack tip contacts, closed contact 119, closed contact 112 and normal contact 118, as soon as it assumes this position in its to-and-fro movement, and the winding of tip supervisory relay 116 to ground. The closing of this circuit will energize supervisory relay 116 and, by moving its contact 115 to its alternate position, interrupt the circult through the supervisory lamp 11 1 to cause its extinguishment and close a circuit through electromagnet E, which controls thespring contacts of set 8 and the catchbar 66. This circuit is completed from the live pole of the battery B, through the winding of said electromagnet, alternate contact 115 of tip supervisory relay 116, and closed contact 113 of sleeve supervisory relay 105 to ground. Prior to the energization' of electromagnet E, the pin 65 on the key 71:, and the associated projections in the catch-bar 66, occupy the position illustrated in Fig. 11. As soon as the electromagnet E is ener ized, its armature is attracted and catch-bar 66 is moved to the left, as viewed in Fig. 7, against the tension of its spring 74 and held inthat position by the continued energization of the magnet. This move- 7 ment of the catch-bar 66 frees the pin 65 of the key 70 and allows it to return, under the action of its returning spring 56, toward its normal position. Its complete restoration to normal, however, is not accomplished because this movement of the catch-bar has brought the catch 73 into the path of movement of the pin 65, and the latter therefore moves upward only until it engages said catch. The relative position of the parts is such that, when thus engaged, the key 70 is held in its intermediate or indicating position. If then, at any time before the connection is taken down, it becomes necessary to again signal the party at substation M,

the operator'can readily see that key 70 was the last depressed, since no other keys will occupy this intermediate position at this time. The movement of the armature 86 of the electromagnet E completes the talking circuit through the link-circuit strands by bringing the contacts 9293 and 96--97 of sets into engagement; and will also cause contacts 94-95 to engage and thereby provide a new path for current through the electromagnet E by way of said contacts and closed contact 113 of supervisory relay 105 to ground. At the end of conversation, the parties restore their receivers to their hooksand thereby produce the customary disconnect signal. As soon as the operator remov'esthe plug P from the jack J, the previous circuit through the sleeve supervisory relay 105 and the cut-off relay 102 will be interrupted with a consequent interruption of the circuit through electromagnet E at contact 113 of said supervisory relay. 7

As soon as this magnet is deenergized, its armature 86 and the catch-bar 66 will be restored by the pressure of the spring 741. The return of the catch-bar toward the right will free the pin from the catch 73 and allow the same to return to normal position, as illustrated in Fig. 13. In the operation of the key mechanism, only one key 70 70 or 711 will be depressed at one time. Thus if key 72 is depressed while key is is in its fully depressed position,the

catch-bar 66 will be movedtoward the left by the engagement of the pin 65 of the key Z0 with the inclined face of its associated catch' the key, there will be no tendency to move the catch-bar 66 in a lateral direction and consequently the key 70 will not be moved to an operative position and the previously depressed key 78 will not be disturbed.

Assuming that the line, into the jack of which the plug P has been inserted, is busy, then there will exist at the sleeve contacts of the jacks potential'resulting from the connection of the sleeve contacts of one i of said jacks with the live pole of the battery B, as is usual, either by way of the calling or answering plug of another linkcircuit. This potential will be sufficiently above that of the intermediate tap ofthe battery B so that, upon the insertion of the plug, current will flow from the sleeve contact of the jack, through the sleeve contact of the plug, closed contact 107106, normal contact 10% of supervisory relay 105,

and polarized relay 103 to the intermediate tap of the battery B. This current flow will be of such a direction as to cause the armature contact 109 of the polarized relay to move to the right into engagement with its contact 120, thereby completing a circuit from the live pole of the battery B,

through the lower winding of relay 108 and closed contacts 120-109 to ground. The

closing of this circuit will energize relay 108 to cause it to open its normally closed contact 119 and to close contacts 107 -121,

followed by the opening of contacts 106 107 and the closing of contacts 122123, V

and to move contact 124 from its normal to its alternate position. The opening of contacts 106107 interrupts the path for current through the polarized relay 103; but

since this interruption occurs after the closing of contacts 107121, the relay is maintained in its actuated position by reason of the flow of current through its upper winding, closed contact 1'21107, plug and jack sleeve contacts, and the winding of cut-off relay 102 to ground. The opening of contact 119 interrupts a possible circuit for ringing current. The closing of contact 122 completes a circuit through the winding of supervisory relay 105. The closing of contact 123 completes a circuit by which a characteristic signal is transmitted from the interrupter I over the line of the calling party, as an indication to him that the called-for line is busy. This circuit is of the usual character and includes a primary circuit extending from the live pole of the battery B, through the primary winding of the induction coil 125 in the interrupter I -to ground; and a secondary circuit extend- Since the depression of the ringing key is results in its being locked in its fully depressed position by the catch-bar 66, it will be necessary to actuate said bar before said key can be returned to its normal position. This is preferably done by momentarily energizing the electromagnet E through the agency of the contact 127 of the slow release relay 128 in conjunction with contact 124 of relay 108. Upon the initial energization of relay 108, a circuit is completed through the slow release relay 128 by way of alternate contact 124. This results in the closing of contact 127; but, because the contact 124: occupies its alternate position at this time, no circuit is completed for electromagnet E. However, as soon as the connection is taken down, relay 108 is again deenergized and its contact 12 1 returns to its normal position before contact 127 opens. Consequently a momentary circuit for the electromagnet E is completed through closed contact 127 and normal contact 124. The resulting momentary energization of electromagnet E causes the attraction of its armature with a resulting to-and-itro movement of the catch-bar 66. This movement is suflicient to release the pin of the depressed key and allow the same to return to normal position.

It should be understood that the specific key construction may be modified somewhat without departing from the spirit and scope of my invention and that, in the control of the catch mechanism, the electromagnet E in the second form of the invention might be variously included in circuit.

What I claim as new and desire to secure by Letters Patent of the United States is 1. A telephone key comprising two sets of contacts, an actuating member for one of said sets biased to return to normal until moved beyond a definite point, an actuating member for said other set of contacts, means actuated upon the operation of said latter member to return said former member be yond said definite point to allow it to return to normal under its bias, and electromagnetically controlled means for subsequently restoring said latter member to an indicating position.

2. A telephone key comprising two sets of contacts, a returning spring, an actuating member for one of said sets of contacts acting against the tension of said spring until a definite point in its movement is reached, an actuating member for said other set of contacts, means actuated upon the operation oi said latter member to return said former member beyond said definite point to allow it to return to normal under the action of said spring, and electromagnetically controlled means for subsequently restoring said latter member to an indicating position.

3. A telephone key comprising two sets of contacts, a returning leaf-spring, an actuating lever for oneof said sets of contacts bearing against said spring and acting against its tension until a definite point in the movement of the lever is reached, an actuating member for said other set of contacts, means actuated upon the operation of said member to return said lever beyond said definite point to allow it to return to normal under the action of said spring, and electromagnetically controlled means for subsequently restoring said member to indicating position.

a. A telephone key comprising two sets of contacts, an actuating member for one of said sets biased to return to normal until moved beyond a definite point, an actuating member for said other set of contacts, a member moved during the operation of said latter actuating member against said former actuating member to return said former actuating member beyond said definite point to allow it to return to normal under its bias, and electromagnetically controlled means for subsequently restoring said latter member to an indicating position.

5. A telephone key comprising two sets of contacts, a returning spring, an actuating lever for one of said sets of contacts bearing against said spring and acting against its tension until a definite point in the movement of the lever is reached, an actuating member for said other set of contacts, a member moved during the operation of said actuating member against said lever to return it beyond said definite point to allow it to return to normal under the action of said spring, and electromagnetically controlled means for subsequently restoring said actuating member to an indicating position.

6. A telephone key comprising two sets of contacts, a returning spring, an actuating lever for one of said sets of contacts bearing against said spring and acting against its tension until a delinite point in the movement of the lever is reached, a longitudinally movable springretracted key for actuating said other set of contacts, a member moved by the depression of said key against said lever to return it beyond said definite point to allow it to return to normal under the action of said spring, and electromagnetically controlled means for subsequently restoring said key to indicating position.

7. A telephone key comprising two sets of contacts, a returning spring, an actuating lever for one of said sets of contacts bearing against said spring and acting against its tension until a definite point in its movement is reached, a longitudinally movable sprin -retracted k y for actuating said other sets of contacts, a sliding member driven by the depression of said key against said lever to return it beyond said definite point to allow it to return to normal under the action of said spring, and electromagnetically controlled means for subsequently restoring said key to indicating position.

8. A telephone key comprising a frame having a face-plate and a supportingbar substantially parallel thereto, two sets of spring contacts secured to said bar and extending toward said face-plate, a key-lever projecting through said face-plate and having its lower end acting against the tension of one of the spring contacts of the cooperating set until a definite point in its movement is reached, a longitudinally movable key projecting through said face-plate into proximity to the other set of spring contacts for actuating the same when depressed, a sliding catch-bar lying ad acent to said face plate and provided with an opening having 7 a catch projection, and a pin projecting latorally from said key through said opening into operative relation with said catch projection whereby the de Jression of said key forces said member against the lower end of said key-lever to return it beyond said definite point to allow it to return to normal under the action of said spring.

9. A party line telephone ringing key comprising a frame having a face-plate and a supporting bar extending substantially parallel thereto, a series of sets of spring contacts carried by said bar and extending toward said face-plate, a series of longitudinally movable keys extending through said plate into operative relation to said sets of contacts, longitudinally movable catchbar extending lengthwise of said plate and provided with a plurality of openings having catch projections, pins projecting laterally from said keys through said openings into operative relation with said catch projections, means operated by the depression of any of said keys to move said catch-bar to carry the catch projections thereon out of engagement with any of said pins, and springs for returning said keys to normal position.

'10. A party line telephone ringing key comprising a frame having a face-plate and a supporting-bar extending substantially parallel thereto, a series ofgsets of spring contacts carried by said bar and extending.

toward said face-plate, a series of longitudinally movable keys extending through said plate into operative relation to said sets of contacts, a longitudinally movable catch-bar extending lengthwise of said plate and provided with a plurality of openings having catch projections, pins projecting laterally from said keys through said openings into operative relation with said catch projections, a bar parallel to said catchbzir and having slots through which said pins pass and by which they are guided, means operated by the depression of any of said keys to move said catch bar to carry the catch projections thereon out of ngagement with any of said pins, and'springs for returnin said keys to normal position; 7

11. i i party line telephone ringing key comprising a frame having a face-plate and a supporting-bar extending substantially out of engagement with any of said pins,

springs for returning said keys to normal position, a set of spring contacts extending toward said face-plate from one end of said frame, a key-lever for actuating said contacts, and means operated upon the movement of said catch-bar to return said key lever to its normal position. i

12. A party line telephone ringing key comprising a frame having a face-plate and a supporting-bar extending substantially parallel thereto, a series of sets of spring contacts carried by said bar and extending toward said face-plate, a series of longitudinally movable keys extending through sald plate into operative relation to said sets of contacts, pins projecting laterally from said keys, a. longitudinally movable catch-bar extending lengthwise of said plate and provlded wlth slotted openlngs wider than said p1ns, staggered pro ections extending from opposite whisk of said openings.

and shoulderedso as toengage said pins, a spring for yieldingly pressing said catchbar against said pins, inclined faces on the walls of said openings against which said pins are adapted to press, upon the depressionof the keys, tomove said catch-bar against the tension of said spring, and springs for returning said keys to normal position; I j r j 13. A telephone key comprising a set of spring contacts, a reciprocating actuating key therefor, a sliding catch-bar movable transversely, of said key, a plurality of catch projections on said bar, a cooperating projection on said. key, and electromagnetic means independent of said key for positively actuating said catch-bar.

14. A telephone key comprising a set of spring contacts, a reciprocating actuating key-therefor, a sliding catch-bar movable ransversely of said key and provided with a' slot extending lengthwise of said key, catch projections extending from the walls of said opening, a pin projecting from said key through said slot into operative relation to saidc'atch projections, and means independent of said key for actuating said catch-bar V r l 15. A telephone key comprising two sets of contacts, a lever for operating one of said sets of contacts, biased to return to normal when moved therefrom, means for holding said lever in actuated pcsitiomalongitudie nally movable key for said other set of contacts operative, when depressed. to release said lever, ,and electromagnetically controlled means for subsequently restoring said key to an indicating position.

, 16. A telephone key comprising two sets of contacts, a lever for operating one of said sets of contacts, biased to return to normal when moved therefrom, a spring member for holding said, lever in its fully operated position, a longitudinally movable key for operating said other set of contacts, means actuated by the operation. of said key to release said lever, and electromagnetically controlled means for subsequently restoring said key to an indicating position.

17. A telephone key comprising two sets. I of contacts, a lever for operatmg one of sald sets of contacts, holding means effective mounted adjacent to said listening key, a

reciprocating member common to said'ringposition, a plurality of ringing keys individual to said listening key, means whereby the actuation of any ringing key restores said listening key to normal, and electromagnetically controlled means for subsequently restoring said actuated ringing key to an indicating position.

20. A telephone key comprising two sets of contacts, an actuating member for operating one of said sets of contacts, biased to return to normal when moved therefrom, means for holding said member in actuated position, an actuating member for operating the'other set of contacts, and a pair of sliding bars, one operative to free said first actuated member in response to the operation of the second actuating member, and the other operative to hold said second member in clifferent positions.

21. A telephone key comprising two sets of contacts, an actuating member for operating one of said sets of contacts, biased to return to normal when moved therefrom, means for holding said member in actuated position. an actuating member for operating the other set of contacts, a pair of sliding bars, one operative to free said first actuated member in response to the operation of the second actuating member. and the other operative to hold said second member in different positions, and electromagnetic-ally controlled means for operating said second bar.

22. In a selective ringing key, the combination with a plurality of plungers and associated sets of contact springs adapted to be individually actuated thereby, of transversely extending detents respectively pro.- vided upon said plungers, a universal slidebar equipped with angularly disposed recesses and under-cut points associated with said detents, a light spring opposing the longitudinal movement of said bar, and a slotted member accommodating the detents to prevent rotation of the plunger and insure the actuation of the slide-bar, substantially as and for the purpose set forth.

23.'The combination with a plurality of spring retracted plunger rods, each provided with a contact operating plunger, of contacts individual to each plunger and arranged to be operated thereby, a plate cooperating with'said plunger for locking said plunger rods, acontact common to said plunger rods, and a second plate movable by said plungers to control said common contact.

7 porting frame, suitable contacts carried 24:. A telephone key comprising .a supporting frame, suitable contacts carried thereby, a spring returned actuating member for said contacts having three operating positions, means comprising an endwise slidable bar extending lengthwise of the frame for holding said member in its second and third positions when moved.

thereto, and means for operating said hold ing means.

25. A telephone key comprising a supthereby, a spring returned actuating member for said contacts having three operating positions, means comprising an endwise slidable bar extending lengthwise of the frame for holding said member in its sec-" 0nd and third positions when moved thereto,

and electromagnetically actuated means for operating said holding means.

26. A telephone key comprising a supportlng frame, suitable contacts carr ed thereby, a sprmg returned actuating member for said contacts having three operating positions, and an electromagnetically actuated endwise slidable bar extending lengthwise of the frame provided with catches for catches for severally holding said member in two of said operating positions, and means for simultaneously disengaging one of said catches and movlng the other 1nto engaging position to thereby allow the movement of said member from one operating position to another. 28. A telephone key comprising a supporting frame, suitable contacts carried thereby, a spring returned actuating member for sa d contacts having three operating positions. a spring controlled endwise slidable catch member provided with a pair of catches for severally holding said member in two said operating positions, and electromagnetically actuated means for simultaneously disengaging one of said catches and moving the other into engaging position to thereby allow the movement of said memberfrcm one-operating position to another.

29. A telephone ringing key comprising a supporting frame, suitable contacts car ried thereby, a spring returned actuating member for said contacts having a ringing and two other operating positions, a spring returned endwise slidable bar for holding said actuating member in its ringing position when once moved thereto, and means.

for subsequently freeing said member and allowmg it to assume another of itssaid two other operating positions, means including an endwise slidable catch bar ior holding said actuating member in its ringing position when once'moved thereto, and electromagnetically actuated means for sub sequently freeing said member and allowing it to assume another of its said operating positions. I j Y 31. A telephone key comprising a sup porting frame, suitable contacts carried thereby, a'spring returned actuating member for said contacts having three operating positions, means including an endwise slidable catch bar for holding said member inits second and thirdposition when moved thereto, means for operating said last means and an additional contact operated by said operating means. r

32. A telephone key comprising a supporting frame, suitable contacts secured thereto, an actuating member for said contacts having a plurality of operating pcsi tions, an endwiseslidable catch member for holding said actuating member in different operating fpositions, means for operating said catch member, and additional spring contacts actuated by said last means.

38. A party line telephone key comprising a supporting frame, sets of spring contacts carried thereby, actuating members for said sets of spring contacts each having a plurality of operating positions-an end,- wise slidable bar mechanism extending lengthwise of said frame operatively related to said actuated members for holding them in different positions, means for operating contacts operated by said last means 34. A telephone ringing key comprising a supporting frame, suitable contactscarried thereby, a spring returned actuating mem ber for said contacts having a ringing and two other operating positions, anelectrosaid bar mechanism, andadditional spring magnetically endwise slidable catch mechanism operative-whenin one position'to hold said member in its ringing position and when in another'position to hold said member in another of its operating positions.

In witness whereof, I hereunto subscribe 4 my name this 5th day'ofMarch, 1906. V

7 WILLIAM KAISLING. Witnesses:

CAROLYN WEBER, V THOMAS H. FERGUSON.

Copies of this patent may be obtained tor five cents each, by addressing the Commissioner of Patents,

' Washington, D. G. V 

